This invention relates to crop irrigation and, more particularly, to an irrigation hose and a method for its construction.
Irrigation of crops is well known and has been in use since early history. Some irrigation systems which are currently in wide use are field flooding, furrow flooding, and sprinkler systems. These prior art systems, however, tend to waste water, to wash away nutrients, to compact soil, to aid the growth of weeds, to require considerable labor to operate, and to supply water to the irrigated crops at undesirable rates.
In order to reduce the problems inherent in the prior art systems referred to above, trickle irrigation has come into widespread use. Unlike the previous systems which distribute excessive water over wide areas, trickle irrigation systems supply water at a slow controlled rate to the root zone of the particular plant being irrigated. Typically, this is accomplished by providing a small water outlet at each plant which allows a limited dripping or flowing of water directly to the root zone of the particular plant. Since evaporation, run-off, over-watering, and watering beyond the root zone is eliminated by the use of trickle irrigation systems, substantial water savings are realized. Additionally, trickle irrigation results in savings in fertilizers and chemicals which may be applied without being washed away, thereby improving the quantity and quality of the crops, and trickle irrigation also results in less salt deposit in the root zone because less water is used.
There are two major types of trickle irrigation systems in general use today. One prior art trickle irrigation system involves the use of fittings, or emitters, which are designed with long restricting passages through which water must pass to an outlet. Such emitters, however, are relatively costly, and a more general type of system used in the prior art is the continuous hose system. In one type of continuous hose system, hoses made of porous material are used and the water in the hose seeps through the hose to the zone being irrigated. Other types of prior art continuous hose systems involve the use of hoses of non-porous material, which have outlet holes spaced along their length. The outlet holes in the prior art hoses must be small in order to maintain a desired flow rate, and they tend to become clogged with silt or precipitating chemicals carried in the water. Attempts have been made in the prior art to provide continuous hose systems which are not susceptible to such clogging. The present invention is of the continuous hose type in which clogging is successfully obviated.